Mr King, who put his successful comedy career on hold to campaign on mental health issues, said on Thursday unless Mr Boyed told you, there would have been no way to know he was unwell.

"One of the biggest problems we have is this myth there are signs," he told The AM Show. "If someone is down in the dumps, they're in the corner, they're put off their food, they're not sleeping - guess what? That's the flu. There are no signs. There is one sign, and one sign only - and that sign is if I tell you.

"Now the problem we have in New Zealand society and all around the world is the problem isn't the person in crisis. It's the rest of us who aren't in crisis, but whose often judgemental attitude is having the biggest effect."

A Kiwi crisis

New Zealand has one of the highest suicide rates in the developed world, and it hasn't improved at all in the last decade. In the 12 months to August last year, 606 Kiwis took their own lives.

Mike King.Photo credit: The AM Show

While most victims are men, women are eight times more likely to attempt suicide, says Mr King, who gave a harrowing example of how our inability - or unwillingness - to listen can have a devastating impact on those who are suffering.

"A father came to me late last year to tell me about his son. He said, 'My son came from school and he said one of his friends was suicidal. My response to him was, 'What the hell's the matter with you kids today? We didn't have any of this crap when I was growing up. Stay away from that kid. If he wanted to take his own life, he would.'

"Sadly for that dad, there was no other kid. He didn't find that out until he read his son's notes. So we all need to be very aware of the things that we are saying to friends when they come to us to talk about these things."

'Normalising the inner critic'

Mr King said while he didn't vote for the present Government - he didn't vote at all - more has been done to fix the health system in the past year than the previous nine.

But there's a long way to go. Presently he says the health system divides people into two categories - 'normal' and 'crisis' - but there should be a third.

"Our mental health frontline workers are Formula 1 mechanics. They are the best in the business… [but] they are currently swamped with Toyota Corollas that need an oil change. We need to have three stages of care - not critical and normal, as it currently is.

"More work needs to be done in the prevention area. More work needs to be done talking about normalising the inner critic, letting people know you're allowed to have a suicidal thought - this sounds really bad, but you're allowed to have a suicidal thought... I know 90 percent of New Zealanders have had a suicidal thought.

"Even worse, just because you have that thought, you are classified as mentally ill. Having a suicidal thought doesn't make you mentally ill - it makes you human.

"Everyone is allowed to think. A thought is just a thought, but we're putting thoughts into categories now - good thought, bad thought. What happens when you tell someone they can't think of something? They think about it."

Greg Boyed.Photo credit: TVNZ

And that, he says, lets the inner critic we all have get out of control.

"In normal people your inner critic will undermine your logical thinking and have you second-guessing the decisions you make throughout the day…

"But in people like me - people with rejection issues, people who have constantly thought themselves not good enough - our inner critic is a bully. It's constantly telling us we're useless. It wants to isolate us, put us in rooms by ourselves so we're eventually sitting there going, 'You know what? What's the point?'"

The key he says is being able to talk to someone about it, without fear of being judged or rejected.

"The fact of the matter is 80 percent of people who have recurring thoughts of suicide never ask for help, ever. Why? They're worried about what other people will think, they're worried about what other people will say, they're worried about what other people will do with that information. In other words… they're worried about us."

He says while fixing the health system will take time, the biggest change will come from everyday Kiwis becoming more accepting of mental illness.

"There's one sign and one sign only people are suicidal - if they tell you. And the only they're going to tell you is if you have kindness in your heart and make it okay for people to talk."